docs: def getGuestList(request):
      '''
      This function handles the filtering of available eventregistration-related
      invoice items and is used on the revenue reporting form.
      '''
      if not (
          request.method == 'POST' and
          request.POST.get('guestlist_id') and
          request.POST.get('event_id') and
          request.user.is_authenticated and
          request.user.has_perm('guestlist.view_guestlist')
      ):
          return JsonResponse({})
  
      guestList = GuestList.objects.filter(id=request.POST.get('guestlist_id')).first()
      event = Event.objects.filter(id=request.POST.get('event_id')).first()
  
      if not guestList or not event:
          return JsonResponse({})
  
      return JsonResponse({
          'names': guestList.getListForEvent(event),
      })